I was able to fix the nav log issue. I am not sure why it went blank or what the issue was, especially with the Nevada Bush trip, I did not have any issue with the Patagonia or Alaska trips.
The solution is not hard but time consuming as it involves finding the last working flight and using copy and paste to add all of the missing information to the last flight completed. Knowing nothing about the programming, it would appear that with each leg or flight the current record is created from the previous record and if there is an issue in the transfer of information the Nav Log is lost. Providing details in this forum might be hard as it is one of those things that would take me 5 minutes to show you and an hour to explain it in writing.